powerpc/perf/hv-24x7: Break up single_24x7_request
[firefly-linux-kernel-4.4.55.git] / arch / powerpc / perf / hv-24x7.c
index 9445a824819ea7f919fdc4191b561e07c07bd49c..46be032f60ad1ce138f81010e65af13300695c8c 100644 (file)
@@ -142,6 +142,15 @@ static struct attribute_group event_long_desc_group = {
 
 static struct kmem_cache *hv_page_cache;
 
+/*
+ * request_buffer and result_buffer are not required to be 4k aligned,
+ * but are not allowed to cross any 4k boundary. Aligning them to 4k is
+ * the simplest way to ensure that.
+ */
+#define H24x7_DATA_BUFFER_SIZE 4096
+DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
+DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
+
 static char *event_name(struct hv_24x7_event_data *ev, int *len)
 {
        *len = be16_to_cpu(ev->event_name_len) - 2;
@@ -152,6 +161,7 @@ static char *event_desc(struct hv_24x7_event_data *ev, int *len)
 {
        unsigned nl = be16_to_cpu(ev->event_name_len);
        __be16 *desc_len = (__be16 *)(ev->remainder + nl - 2);
+
        *len = be16_to_cpu(*desc_len) - 2;
        return (char *)ev->remainder + nl;
 }
@@ -162,6 +172,7 @@ static char *event_long_desc(struct hv_24x7_event_data *ev, int *len)
        __be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2);
        unsigned desc_len = be16_to_cpu(*desc_len_);
        __be16 *long_desc_len = (__be16 *)(ev->remainder + nl + desc_len - 2);
+
        *len = be16_to_cpu(*long_desc_len) - 2;
        return (char *)ev->remainder + nl + desc_len;
 }
@@ -239,14 +250,12 @@ static unsigned long h_get_24x7_catalog_page_(unsigned long phys_4096,
                                              unsigned long index)
 {
        pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
-                       phys_4096,
-                       version,
-                       index);
+                       phys_4096, version, index);
+
        WARN_ON(!IS_ALIGNED(phys_4096, 4096));
+
        return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
-                       phys_4096,
-                       version,
-                       index);
+                       phys_4096, version, index);
 }
 
 static unsigned long h_get_24x7_catalog_page(char page[],
@@ -300,6 +309,7 @@ static ssize_t device_show_string(struct device *dev,
        struct dev_ext_attribute *d;
 
        d = container_of(attr, struct dev_ext_attribute, attr);
+
        return sprintf(buf, "%s\n", (char *)d->var);
 }
 
@@ -314,6 +324,7 @@ static struct attribute *device_str_attr_create_(char *name, char *str)
        attr->attr.attr.name = name;
        attr->attr.attr.mode = 0444;
        attr->attr.show = device_show_string;
+
        return &attr->attr.attr;
 }
 
@@ -387,7 +398,6 @@ static struct attribute *event_to_attr(unsigned ix,
                a_ev_name = kasprintf(GFP_KERNEL, "%.*s%s__%d",
                                (int)event_name_len, ev_name, ev_suffix, nonce);
 
-
        if (!a_ev_name)
                goto out_val;
 
@@ -872,6 +882,7 @@ static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
        uint64_t catalog_version_num = 0;
        void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
        struct hv_24x7_catalog_page_0 *page_0 = page;
+
        if (!page)
                return -ENOMEM;
 
@@ -976,31 +987,104 @@ static const struct attribute_group *attr_groups[] = {
        NULL,
 };
 
-DEFINE_PER_CPU(char, hv_24x7_reqb[4096]) __aligned(4096);
-DEFINE_PER_CPU(char, hv_24x7_resb[4096]) __aligned(4096);
+static void log_24x7_hcall(struct hv_24x7_request_buffer *request_buffer,
+                       struct hv_24x7_data_result_buffer *result_buffer,
+                       unsigned long ret)
+{
+       struct hv_24x7_request *req;
+
+       req = &request_buffer->requests[0];
+       pr_notice_ratelimited("hcall failed: [%d %#x %#x %d] => "
+                       "ret 0x%lx (%ld) detail=0x%x failing ix=%x\n",
+                       req->performance_domain, req->data_offset,
+                       req->starting_ix, req->starting_lpar_ix, ret, ret,
+                       result_buffer->detailed_rc,
+                       result_buffer->failing_request_ix);
+}
+
+/*
+ * Start the process for a new H_GET_24x7_DATA hcall.
+ */
+static void init_24x7_request(struct hv_24x7_request_buffer *request_buffer,
+                       struct hv_24x7_data_result_buffer *result_buffer)
+{
+
+       memset(request_buffer, 0, 4096);
+       memset(result_buffer, 0, 4096);
+
+       request_buffer->interface_version = HV_24X7_IF_VERSION_CURRENT;
+       /* memset above set request_buffer->num_requests to 0 */
+}
 
-static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix,
-                                        u16 lpar, u64 *res,
-                                        bool success_expected)
+/*
+ * Commit (i.e perform) the H_GET_24x7_DATA hcall using the data collected
+ * by 'init_24x7_request()' and 'add_event_to_24x7_request()'.
+ */
+static int make_24x7_request(struct hv_24x7_request_buffer *request_buffer,
+                       struct hv_24x7_data_result_buffer *result_buffer)
 {
        unsigned long ret;
 
        /*
-        * request_buffer and result_buffer are not required to be 4k aligned,
-        * but are not allowed to cross any 4k boundary. Aligning them to 4k is
-        * the simplest way to ensure that.
+        * NOTE: Due to variable number of array elements in request and
+        *       result buffer(s), sizeof() is not reliable. Use the actual
+        *       allocated buffer size, H24x7_DATA_BUFFER_SIZE.
         */
-       struct reqb {
-               struct hv_24x7_request_buffer buf;
-               struct hv_24x7_request req;
-       } __packed *request_buffer;
-
-       struct {
-               struct hv_24x7_data_result_buffer buf;
-               struct hv_24x7_result res;
-               struct hv_24x7_result_element elem;
-               __be64 result;
-       } __packed *result_buffer;
+       ret = plpar_hcall_norets(H_GET_24X7_DATA,
+                       virt_to_phys(request_buffer), H24x7_DATA_BUFFER_SIZE,
+                       virt_to_phys(result_buffer),  H24x7_DATA_BUFFER_SIZE);
+
+       if (ret)
+               log_24x7_hcall(request_buffer, result_buffer, ret);
+
+       return ret;
+}
+
+/*
+ * Add the given @event to the next slot in the 24x7 request_buffer.
+ *
+ * Note that H_GET_24X7_DATA hcall allows reading several counters'
+ * values in a single HCALL. We expect the caller to add events to the
+ * request buffer one by one, make the HCALL and process the results.
+ */
+static int add_event_to_24x7_request(struct perf_event *event,
+                               struct hv_24x7_request_buffer *request_buffer)
+{
+       u16 idx;
+       int i;
+       struct hv_24x7_request *req;
+
+       if (request_buffer->num_requests > 254) {
+               pr_devel("Too many requests for 24x7 HCALL %d\n",
+                               request_buffer->num_requests);
+               return -EINVAL;
+       }
+
+       if (is_physical_domain(event_get_domain(event)))
+               idx = event_get_core(event);
+       else
+               idx = event_get_vcpu(event);
+
+       i = request_buffer->num_requests++;
+       req = &request_buffer->requests[i];
+
+       req->performance_domain = event_get_domain(event);
+       req->data_size = cpu_to_be16(8);
+       req->data_offset = cpu_to_be32(event_get_offset(event));
+       req->starting_lpar_ix = cpu_to_be16(event_get_lpar(event)),
+       req->max_num_lpars = cpu_to_be16(1);
+       req->starting_ix = cpu_to_be16(idx);
+       req->max_ix = cpu_to_be16(1);
+
+       return 0;
+}
+
+static unsigned long single_24x7_request(struct perf_event *event, u64 *count)
+{
+       unsigned long ret;
+       struct hv_24x7_request_buffer *request_buffer;
+       struct hv_24x7_data_result_buffer *result_buffer;
+       struct hv_24x7_result *resb;
 
        BUILD_BUG_ON(sizeof(*request_buffer) > 4096);
        BUILD_BUG_ON(sizeof(*result_buffer) > 4096);
@@ -1008,63 +1092,26 @@ static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix,
        request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
        result_buffer = (void *)get_cpu_var(hv_24x7_resb);
 
-       memset(request_buffer, 0, 4096);
-       memset(result_buffer, 0, 4096);
+       init_24x7_request(request_buffer, result_buffer);
 
-       *request_buffer = (struct reqb) {
-               .buf = {
-                       .interface_version = HV_24X7_IF_VERSION_CURRENT,
-                       .num_requests = 1,
-               },
-               .req = {
-                       .performance_domain = domain,
-                       .data_size = cpu_to_be16(8),
-                       .data_offset = cpu_to_be32(offset),
-                       .starting_lpar_ix = cpu_to_be16(lpar),
-                       .max_num_lpars = cpu_to_be16(1),
-                       .starting_ix = cpu_to_be16(ix),
-                       .max_ix = cpu_to_be16(1),
-               }
-       };
-
-       ret = plpar_hcall_norets(H_GET_24X7_DATA,
-                       virt_to_phys(request_buffer), sizeof(*request_buffer),
-                       virt_to_phys(result_buffer),  sizeof(*result_buffer));
+       ret = add_event_to_24x7_request(event, request_buffer);
+       if (ret)
+               return ret;
 
+       ret = make_24x7_request(request_buffer, result_buffer);
        if (ret) {
-               if (success_expected)
-                       pr_err_ratelimited("hcall failed: %d %#x %#x %d => "
-                               "0x%lx (%ld) detail=0x%x failing ix=%x\n",
-                               domain, offset, ix, lpar, ret, ret,
-                               result_buffer->buf.detailed_rc,
-                               result_buffer->buf.failing_request_ix);
+               log_24x7_hcall(request_buffer, result_buffer, ret);
                goto out;
        }
 
-       *res = be64_to_cpu(result_buffer->result);
+       /* process result from hcall */
+       resb = &result_buffer->results[0];
+       *count = be64_to_cpu(resb->elements[0].element_data[0]);
 
 out:
        return ret;
 }
 
-static unsigned long event_24x7_request(struct perf_event *event, u64 *res,
-               bool success_expected)
-{
-       u16 idx;
-       unsigned domain = event_get_domain(event);
-
-       if (is_physical_domain(domain))
-               idx = event_get_core(event);
-       else
-               idx = event_get_vcpu(event);
-
-       return single_24x7_request(event_get_domain(event),
-                               event_get_offset(event),
-                               idx,
-                               event_get_lpar(event),
-                               res,
-                               success_expected);
-}
 
 static int h_24x7_event_init(struct perf_event *event)
 {
@@ -1133,7 +1180,7 @@ static int h_24x7_event_init(struct perf_event *event)
        }
 
        /* see if the event complains */
-       if (event_24x7_request(event, &ct, false)) {
+       if (single_24x7_request(event, &ct)) {
                pr_devel("test hcall failed\n");
                return -EIO;
        }
@@ -1145,7 +1192,7 @@ static u64 h_24x7_get_value(struct perf_event *event)
 {
        unsigned long ret;
        u64 ct;
-       ret = event_24x7_request(event, &ct, true);
+       ret = single_24x7_request(event, &ct);
        if (ret)
                /* We checked this in event init, shouldn't fail here... */
                return 0;
@@ -1153,15 +1200,22 @@ static u64 h_24x7_get_value(struct perf_event *event)
        return ct;
 }
 
-static void h_24x7_event_update(struct perf_event *event)
+static void update_event_count(struct perf_event *event, u64 now)
 {
        s64 prev;
-       u64 now;
-       now = h_24x7_get_value(event);
+
        prev = local64_xchg(&event->hw.prev_count, now);
        local64_add(now - prev, &event->count);
 }
 
+static void h_24x7_event_read(struct perf_event *event)
+{
+       u64 now;
+
+       now = h_24x7_get_value(event);
+       update_event_count(event, now);
+}
+
 static void h_24x7_event_start(struct perf_event *event, int flags)
 {
        if (flags & PERF_EF_RELOAD)
@@ -1170,7 +1224,7 @@ static void h_24x7_event_start(struct perf_event *event, int flags)
 
 static void h_24x7_event_stop(struct perf_event *event, int flags)
 {
-       h_24x7_event_update(event);
+       h_24x7_event_read(event);
 }
 
 static int h_24x7_event_add(struct perf_event *event, int flags)
@@ -1191,7 +1245,7 @@ static struct pmu h_24x7_pmu = {
        .del         = h_24x7_event_stop,
        .start       = h_24x7_event_start,
        .stop        = h_24x7_event_stop,
-       .read        = h_24x7_event_update,
+       .read        = h_24x7_event_read,
 };
 
 static int hv_24x7_init(void)